hewitt



3 Sheets--Sheet 1.

(No Model.)

W. HEWITT. V MANUFACTURE 0]? TILES AND APPARATUSTHEREFOR.

Patented Feb. 8. 1898.

(No Model.) 3 Sheets-Sheet 2.

W. HEWITT. MANUFACTURE OF TILES AND APPARATUS THEREFOR. No. 598,781. Patented Feb. 8, 1898 AM I? A fl Z'ffiessesv v I ZZzz/erz/w:

(No Model.) 3 Sheets-Sheet 3.

W. HEWITT.

MANUFACTURE OF TILES AND APPARATUS THEREFOR.

Patented Feb. 8

QM W THE NORRIS PETERS co. wnomuwm, WASHINDTON. n. c.

Nirnn STATES PATENT rrrcn.

WILLIAM HEWITT, OF HEREFORD, ENGLAND.

SPECIFICATION forming part of Letters Patent No. 598,781, dated February 8, 1898.

Application filed June 21, 1897. Serial No. 641,700. (No model.)

To all whomit may concern.-

Be it known that 1, WILLIAM HEWITT, a

. subject of the Queen of Great Britain, residing at Hereford, England, have-invented new and useful Improvements in the Manufacture of Tiles and Apparatus Therefor, of which the following is a specification.

This invention relates to the manufacture of tiles with undercut recesses therein and to apparatus for forming such recesses.

In carrying out my invention I employ a circular block the face of which is formed with a number of undercut serrations or ribs, the said block being provided on its periphery with spirally-arranged lugs adapted to work in corresponding recesses or grooves in the top or bottom plate of the die, as the case may be. Suitable means, such as springs, normally keep the ribbed surface of the block projected the required distance beyond the surface of the plate upon which the back of the tile is molded and known as the back plate. The ribs on the block are so shaped that they will free themselves from the recesses in the tiles. In some cases the back plate is depressed to form the undercut recesses in the tile.

To enable my invention to be fully understood,I,will describe the same by reference to the accompanying drawings, in-which Figure 1 is a sectional elevation of a tilemold constructed according to my invention and of the kind wherein the circular block for forming the undercut recesses in the tiles is on the top die and adapted to free itself from the undercut recesses formed in the tile by moving outward relatively with the said die, and Fig. 2 is an under side or face view of the topdie. Fig; 3 is an elevation of the circular block detached, and Fig. 4 is a face view of the same. Fig. 5 is a sectional view of the back plate in which the circular block works, and Fig. 6 is an under side View of the said back plate. Fig. 7 is a view of the back of a tile formed in the above-described apparatus, and Fig. Sis an edge view of the same. Fig. 9 is a sectional elevation of a tile-mold wherein the circular block is arranged in the lower die and adapted to free itself from the undercut recesses in the tile by moving inward relatively with the said die. Fig. 10 is a view, similar to Fig. 9, of a mold wherein a modified form of circular block is used and wherein the die is adapted to be moved outward relatively with the said circular block to free the latter from the tile. Fig. 11 is a plan view of the same below the line 11 11, Fig. 10. Figs. 12 and 13 are respectively an elevation and a plan of the circular block detached, and Figs. 14 and 15 are respectively the material of which the tiles are formed into the mold-box, and d is the circular block for forming the undercut recesses.

In the arrangement of my invention shown in Figs. 1 to 6 the top die 0, which is formed in two parts connected by screws 6 e, has formed in it a circular recess f to receive the circular block (1,- Figs. 3 and 4. In the walls of the said recess in the back part of the die is a series of spirally-arranged slots 9 9, Figs. 5 and 6, in which work the spirally-arranged lugs h h on the circular block (1, the front or face part of the die 0 serving as an abutment against which the lugs h h impinge, as shown in Fig. 1, to limit the outward movement of the circular block 01 under the action of a spring *6, arranged behind the said block. As shown, this spring does not bear directly against the block d, but against a plate j, piv-' otally mounted upon a pin is on the back of the said block in order that the spring shall not have a tendency to impart a rotary movement to the block in either direction, but leave it absolutely free to partially rotate in the deand lugs 71. plate and pin can be dispensed with, the spring, which may be of any suitable kind, acting directly upon the block.

It will be noticed that the recess f, in which the circular block d moves, is of such depth as to permit of a backward movement of the said circular block against the pressure of the spring '5.

sired manner under the action of the slots 9 5 If desired, however, the said Z Z are the radial ribs or projections upon the surface of the circular block cl, and m m are the grooves between the said ribs. These ribs are undercut on one side to form lips '11. n, and the tops or shoulders of the ribs and the bottoms of the grooves are rounded, as shown in Fig. 1, so that the highest parts of the shoulders and the deepest parts of the grooves are a short distance back from the lips, as clearly shown in Fig. 1. The object of this formation of the ribs and grooves is that when the circular block rotates in the required direction to free itself from the recesses formed in the tile there should be no abradin g of the bottoms of the recesses in the tile or destruction of the sharpness of the lips upon the undercut edges of the said recesses. The said ribs Z Z and the lugs h it must be arranged in such relation to each other that when in the downward movement of the die to compress the material in the mold the circular block is pressed back into the recess f against the pressure of the spring 1' and there-- by partially rotated. The lips n of the ribs Z shall be forced toward the material in order to insure the molding of sharp edges to the recesses in the tile,and that when the pressure upon the molded tile is relieved the said block shall rotate so as to move the lips 72 away from the correspondingly-molded lips upon the tile. The upper die having been lifted, the lower die is raised to bring the tile out of the mold.

The tile made in the apparatus hereinbefore described is shown in Figs. 7 and 8.

Although I have shown the upper die as the back plate, the arrangement of the dies may be reversed, so that the lower die is the back plate.

In the modification of my invention shown in Fig. 9 the circular block d, instead of being carried in the upper die 0, is carried in the lower die I), and is designed to be moved below the surface of the said die I) in order to withdraw it from the molded tile. To permit of this, I employ What is known as double discharging-gear -that is to say, of mechanism which is capable of positively moving the die b and the circular block d relatively with one another, the die I) being connected by a tube 1) with one part of the discharginggear and the circular block cl by a rod 61, passing through the said tube and connected to another part of the discharging-gear. It is to be understood that the circular block when moved relatively with the die 19 rotates slightly upon its axis, owing to the arrangement of the spiral lugs h thereon working in grooves g g. In making a tile in this apparatus the die I) and circular block d being in the relative position shown in Fig. 9, the required quantity of material is introduced into the mold and compressed to the desired extent by the top die a. The circular block 61 is then drawn below the surface of the die I) to free it from the tile, and then the die I), with the block 01 still below its surface, is raised to bring the tile out of the mold. The tile made in this mold is the same as that shown in Figs. 7 and 8.

In the modification of my invention shown in Figs. 10 to 15 the circular block 01 is represented as provided with a series of spiral lugs 0 0, Figs. 12 and 13, which are adapted to work in corresponding openin gs p p, formed in the die Z), as shown in Figs. 14 and 15, in such a manner that the relative movement of the die and circular block causes the axial rotation of the latter. The said lugs 0 0 are of such length that when the surfaces of the circular block between the said lugs are in contact with the under side of the surfaceplate of the die I) the ends of the lugso owill project above the surface of the die, as indicated in Fig. 10, the desired extent to form the recesses in the tile. A spring g, which may be of india-rubber or other suitable material, is arranged in a recess in the circular block d and with its upper end against the under side of the upper part of the die 6 tends to draw the said projecting ends of the lugs 0 0 into the die. In the die 1), below the circular block d, is a series of stop-pins r 0", which rest upon a rigid base-ring s and are of such length that when the die I) is in its lowest position the ends of the lugs 0 0 will project to the desired extent above the surface of the die I). The discharging mechan ism connected to the die I) by the rod b serves by its weight to normally retain the said die in its lowest position, as shown in Fig. 10. The tile having been molded in the usual manner, the die 1) is raised,the circular block remaining stationary as regards a vertical movement, (owing to the spring 61 holding it down against the pins 4" 73) but rotating slightly upon its axis. When the top of the die is level with the top of the lugs 0 0, the bottom of the recess f in the die I) comes into contact with the heads of the pins r r, so that the continued upward movement of the said die to lift the tile out of themold carries the circular block upward with the die. The shape of the recesses-formed in the tile by the circular block used in this modification will be clearly understood by reference to Figs. 16 and 17.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be-performed, I declare that what I claim is 1. The combination with the upper and lower dies, one of said dies having spirallyarranged recesses,of a movable circular block, engaging said recessed die and having spirally-arranged lugs engaging said recesses, whereby the movement of said block with respect to said die will cause said block to rotate, substantially as described.

2. The combination with the upper and lower dies, one of said dies being provided with a circular recess, and spirally-arranged grooves, of a movable block located in said recess and having lugs engaging said grooves, said block being provided on its face with a IIC series of undercut projections or ribs and means for moving said block longitudinally in said recessed die whereby said block is caused to rotate on its longitudinal axis, sub stantially as described.

3. The combination with the upper and lower dies, one of said dies being provided with a circular recess and spiral grooves, of a circular block in said recess provided with lugs engaging said grooves, said block being provided on its face with projections having undercut edges for making recesses with overhanging walls in a tile, and a spring operatively connectedwith said block for moving it in line with its axis, whereby said block will be rotated about its axis by said spiral grooves and lugs, substantially as described.

4. The combination with the upper die provided with a central circular recess, and spirally-disposed grooves in the walls of said recess, of a circular block in said recess having lugs engaging said grooves and having its face provided with undercut projections for forming recesses with overhanging projections, in a tile, a spring in said recess in rear of said block and the lower die, substantially as described.

5. The combination with the upper die provided with a circular recess, and spirally-disposed grooves in the walls of said recess, of a circular block in said recess having lugs engaging said grooves, said block having its face provided with project-ions provided with undercut edges for forming recesses with overhanging walls in a tile, a plate in said circular recess of the die provided with a pin engaging said block in line with its axis ofrotation, a spring in said recess engaging said plate, and the lower die, substantially as described.

WILLIAM HEWITT. Witnesses:

W. J. BLAoKMoN, T. CAREY GRIFFITHS. 

